title: Definition and classification of pulmonary hypertension.
abstract: Pulmonary hypertension is defined as an increase of mean pulmonary arterial pressure ≥25 mmHg at rest as assessed by right heart catheterization. According to different combinations of values of pulmonary wedge pressure, pulmonary vascular resistance and cardiac output, a hemodynamic classification of pulmonary hypertension has been proposed. Of major importance is the pulmonary wedge pressure which allows to distinguish pre-capillary (pulmonary wedge pressure ≤15 mmHg) and post-capillary (pulmonary wedge pressure >15 mmHg) pulmonary hypertension. Pre-capillary pulmonary hypertension includes the clinical groups 1 (pulmonary arterial hypertension), 3 (pulmonary hypertension due to lung diseases and/or hypoxia), 4 (chronic thrombo-embolic pulmonary hypertension) and 5 (pulmonary hypertension with unclear and/or multifactorial mechanisms). Post-capillary pulmonary hypertension corresponds to the clinical group 2 (pulmonary hypertension due to left heart diseases).
authors.affiliation: Faculté de Médecine, Univ Paris-Sud, Le Kremlin-Bicêtre, France, marc.humbert@abc.aphp.fr.
authors.forename: Marc
authors.initials: M
authors.lastname: Humbert
authors.forename: David
authors.initials: D
authors.lastname: Montani
authors.forename: Oleg V
authors.initials: OV
authors.lastname: Evgenov
authors.forename: Gérald
authors.initials: G
authors.lastname: Simonneau
mesh_terms: D000818:Animals; D065627:Familial Primary Pulmonary Hypertension; D006801:Humans; D006976:Hypertension, Pulmonary / Q000145:classification* / Q000209:etiology / Q000503:physiopathology